Self-propelled machine for supporting an oscillating tool

Claim 2

A self-propelled machine to support a tool describing a meandering path along a slot between the edges of two metal sheets disposed end-to-end, comprising: a self-propelled carriage movable along a rail secured to one of the sheets and parallel to said slot; a tool holder supported by said carriage; a reversible electric motor disposed on said carriage; transmission means connecting said motor and tool holder to oscillate the tool holder transversely relative to said slot; an electrical circuit coupled to said reversible motor and adapted for connection to a power source for energizing said motor; reversing switch means in said electrical circuit; and sheet-edge-detecting means connected to the tool holder for oscillation therewith and connected to actuate the reversing switch means for reversing the direction of rotation of said motor to vary the magnitude of tool holder oscillation in response to varying positions of the sheet edges as the carriage moves along the slot; and centering means moving said tool holder laterally of said slot for maintaining the center of oscillation at the center of the slot.

Claim 3

A machine according to claim 1, wherein the detecting means comprising at least one metal body proximity detector consisting of an inductance disposed in a capsule secured to the tool holder.

Claim 4

A machine according to claim 1, wherein the detecting means comprise at least one conductive needle insulated from earth and coupled to said circuit to receive a voltage in operation and which is secured to the tool holder.

Claim 5

A machine according to claim 3, wherein the detecting means comprise two pivotable conductive needles normally parallel to the tool axis and slidable in the direction parallEl to the tool axis.

Claim 6

A machine according to claim 1, wherein the detecting means comprise at least one rod secured to the tool holder and movable to actuate an electrical contact when encountering a sheet.

Claim 7

A butt-welding machine comprising a self-propelled carriage movable along a rail adapted to be secured to one of two adjacent sheets, a reversible electric motor disposed on said carriage, a welding tool holder supported by said carriage, a transmission of the crank and connecting rod type coupled to the reversible motor to oscillate the welding tool holder about an axis substantially parallel to the rail, an electrical circuit connected to the reversible motor for coupling the motor to a power source, reversing switch means disposed in said electrical circuit, sheet-edge-detecting means secured to the tool holder and oscillatable therewith to operate said reversing switch means upon detection of a sheet edge to automatically control the amplitude of the welding tool holder oscillations to a slot width between the two sheets, an auxiliary carriage mounted on the self-propelled carriage for movement transversely of said rail by a second reversible motor, a second electrical circuit for said second reversible motor for coupling the motor to a power source, switch means for controlling starting of the said second reversible motor in either direction and disposed in said second electrical circuit, and crank-throw-detection means mounted adjacent one of the said cranks to actuate said switch means upon crank excursion beyond a predetermined amount to operate said second motor for movement of said auxiliary carriage in order to center the welding tool holder by keeping the axis about which it is oscillatable in the plane of symmetry of the weld.

Claim 8

A butt-welding machine comprising a self-propelled carriage movable along a rail adapted to be secured to one of two adjacent sheets, a reversible electric motor disposed on said carriage, a welding tool holder supported by said carriage, a transmission of the crank and connecting rod type coupled to the reversible motor to oscillate the welding tool holder about an axis substantially parallel to the rail, an electrical circuit connected to the reversible motor for coupling the motor to a power source, reversing switch means disposed in said electrical circuit, sheet-edge-detecting means secured to the tool holder and oscillatable therewith to operate said reversing switch means upon detection of a sheet edge to automatically control the amplitude of the welding tool holder oscillations to a slot width between the two sheets, an auxiliary carriage mounted on the self-propelled carriage for movement transversely of said rail by a second reversible motor, a second electrical circuit for said second reversible motor for coupling the motor to a power source, switch means for controlling starting of the said second reversible motor in either direction and disposed in said second electrical circuit, and crank-throw-detection means mounted adjacent one of the said cranks to actuate said switch means upon crank excursion beyond a predetermined amount to operate said second motor for movement of said auxiliary carriage in order to center the welding tool holder by keeping the axis about which it is oscillatable in the plane of symmetry of the weld.

Claim 9

A welding machine according to claim 6, wherein one of said cranks has a metal lug rigidly secured thereto and said crank-throw-detection means comprises two metal body proximity detectors of adjustable spacing disposed symmetrically on either side of the middle position of the oscillating lug.

Claim 10

A welding machine according to claim 6 further comprising a metal rod which is insulated from earth and to which voltage is applied in operation, the rod being connected to one of the cranks of said transmission, and said crank-throw-detection means including two contacts which have variable spacing and are disposed symmetrically on either side of the middle position of the said rod.

Claim 11

A welding machine according to claim 6 further comprising a metal lug rigidly secured to one of the cranks of the said transmission and said crank-throw-detection means including two adjustably spaced needles from earth and receive voltage and have adjustable spacing and are disposed symmetrically on either side of the middle position of said metal lug and have a voltage applied thereto for causing a current to flow upon contact of said lug with either needle.